The WWII Mystery Behind the 1942 Battle of Los Angeles: Axis Planes, Aliens or Mass Hysteria?

Not even three months after the Japanese attack at Pearl Harbor, Americans on the west coast thought they were under attack. Sirens sounded across Los Angeles in the early morning hours of Feb. 25, 1942. Within minutes, searchlights swept the sky while thousands of air raid wardens rushed to their posts. Then anxious gun crews unleashed hell.

For nearly an hour, anti-aircraft batteries fired a massive barrage that shook windows and rattled nerves across the city. Residents in bathrobes and pajamas went into their yards, looking up at bursting shells overhead. Others jumped out of bed and hid their families in sheds and basements. Some claimed they saw formations of planes, many claimed to have seen strange lights.

When the sun rose over L.A., nothing had been shot down. There were no bomb craters in the city. Yet, the Army had fired over a thousand shells into the sky and five people on the ground were dead.

Japanese Submarine Attack: Los Angeles on High Alert

After American entry into WWII, L.A. was a city on edge. Pearl Harbor shocked the nation. Many on the west coast felt that an enemy invasion could materialize at any moment.

Cities from Seattle to San Diego began defense preparations while the military guarded vital installations. Police and federal agents sent out regular patrols while military personnel guarded the coastline. One soldier noted there were only a few machine guns guarding the entire west coast. 

Hundreds of soldiers were even posted in Walt Disney Studios and Hollywood to protect against enemy saboteurs. The Army posted numerous anti-aircraft batteries throughout the city.

They had reason to fear; the Axis were on a seemingly unstoppable warpath around the world. Japanese submarines prowled the coastline, sinking merchant vessels. On Feb. 23, just one day earlier, submarine I-17 surfaced near Santa Barbara and shelled an oil field. 

Though damage was minimal, enemy forces had struck the continental United States. Panic spread quickly. Even government officials felt there was nothing the military could do to stop the Japanese from overrunning the west coast.

Naval intelligence issued a warning on Feb. 24 advising residents and service members to expect an attack within 10 hours. That evening, residents reported flares going off near defense plants. An alert sounded at 7:18 p.m., only being lifted hours later at 10:23 p.m. The city was on edge.

The Battle of Los Angeles

Shortly after 2 a.m., Army radar crews tracked something 120 miles west of Los Angeles. A blackout was ordered at 2:21 a.m. — only months later would the government enforce blackouts along all coasts. Reports started pouring in — enemy planes near Long Beach, formations at 12,000 feet, a balloon with a red flare over Santa Monica. Scattered reports were sent to nervous gun crews scanning the sky.

Suddenly, at 3:16 a.m., the 37th Coast Artillery Brigade opened fire. Over the next hour, the gun crews fired .50-caliber machine guns and 12.8-pound anti-aircraft shells. Over 1,400 explosive rounds were fired into the sky. Orange tracers streaked upward as explosions broke the darkness. Smoke filled the air throughout the city.

Fighter pilots were put on alert and sent to their planes. They sat ready but never launched as their commanders needed to identify the threat and its direction first.

Three people died in traffic accidents as terrified drivers sped through blacked-out streets while looking skyward. Shrapnel rained down across the city, piercing homes, damaging cars, and even landing in a couple’s bed just after they jumped up to find cover. Two people suffered fatal heart attacks during the commotion. One shell fell back to earth and killed a farmer’s cow.

Numerous injuries were reported, especially amongst air raid wardens rushing to their posts. Some bumped their heads, suffered scrapes and cuts in the darkness, one broke his leg and another broke an arm.

Just as quickly as it had started, the "Great L.A. Air Raid" was over.

Military and Government Offer Conflicting Explanations

The following morning, L.A. citizens found their property damaged, shrapnel everywhere, and even unexploded shells across the city. With no definitive proof as to what just occurred, people began spreading their own theories.

The incident came just six days after President Franklin Roosevelt signed Executive Order 9066 on Feb. 19, which authorized mass incarceration of Japanese Americans. Authorities arrested 20 Japanese Americans for allegedly violating the blackout that night.

Morning newspapers pushed conflicting headlines. The Los Angeles Times declared foreign aircraft had flown over Southern California and drawn “heavy barrages of anti-aircraft fire — the first ever to sound over United States continental soil against an enemy invader.”

But Navy Secretary Frank Knox called it a false alarm caused by “jittery nerves.” Secretary of War Henry Stimson contradicted him, insisting as many as 15 unidentified aircraft had appeared, likely trying to justify the Army’s response. He suggested they might be commercial planes flown by enemy agents from secret airfields in Mexico. He later walked back those claims.

Rep. Leland Ford of Santa Monica demanded a congressional investigation, calling the episode “complete mystification.” As government officials and media outlets clashed, Californians continued fearing Japanese attacks for months after the event.

However, many became angered at the realization that the Army caused the entire incident over nothing. The sheriff faced criticism for arresting Japanese-American civilians when there was no credible threat.

The contradictions persisted for years. After the war ended, Japan confirmed it had flown no aircraft over Los Angeles that night. People continued to ponder what exactly happened that night to cause such a massive military response.

UFO Conspiracy Theories

Years after World War II ended, the incident was popularized by the rise of UFO groups. A photograph the Los Angeles Times published on Feb. 26, 1942, appeared to show searchlights converging on a disc-shaped object — allegedly the source of the mysterious lights many people claimed they saw that night.

But the image had been heavily retouched before publication — a routine practice in 1940s photo departments to improve contrast for newsprint. The original negative showed only faint lights and unclear shapes, no definitive proof of enemy planes or a UFO.

Nevertheless, the photo has persisted among UFO enthusiasts who like to theorize that alien spacecraft may have been responsible for the "air raid."

The famous image would later appear in promotional materials for the 2011 film “Battle: Los Angeles,” cementing its place in pop culture alongside Roswell and Area 51.

The Likely Explanation for the Great L.A. Air Raid

The most credible explanation for the event was the mix of genuine threats from Axis forces, primitive radar technology and raw fear among civilians and military personnel alike. The shelling of the oil facility had proven the danger from the Japanese was real. Radar likely detected weather balloons released for testing, or perhaps nothing at all. 

Once the first nervous gunner felt he saw something and opened fire, the rest of the battery followed his lead. The combination of searchlights, smoke and exploding shells created the illusion of targets where none existed, causing mass confusion and hysteria throughout the city.

The United States Coast Artillery Association later attributed the incident to a lost meteorological balloon that got loose. Once spotted, jumpy gun crews opened fire. A 1983 Air Force history review concluded that war nerves and meteorological balloons likely triggered the incident.

While no Japanese planes flew over L.A. that morning, the threat was very real. Aside from the submarine attack against the oil facility, a Japanese floatplane later launched from a sub and bombed Oregon in an attempt to spark a wildfire. The Japanese also launched thousands of balloons across the Pacific with fire-bombs attached to them, one of which killed an American family. Only a few months after the scare in L.A., Japanese forces invaded Alaska, launching the Aleutians Campaign, the only land combat in the American Theater of WWII.

On the east coast, German submarines decimated American shipping as terrified civilians on the shoreline watched the explosions on the horizon. German saboteurs were captured after landing on the American mainland. Even Italian commandos planned a daring submarine attack against New York Harbor that was only stopped when Italy surrendered.

While not as deadly as other theaters, the American home-front did face threats from the Axis powers which spread fear throughout the nation. The mysterious event over L.A. that morning may not have been axis planes or even aliens, but it shows how wartime conditions affected American citizens.